The Broncos said in a statement that Gibbs died from complications from a stroke. He was surrounded by his family in Phoenix.
"We are deeply saddened by the passing of Alex Gibbs, who had a profound impact on the Denver Broncos and the National Football League as an offensive line coach," the team said. "During his 14 years with the Broncos, Coach Gibbs left a lasting legacy on this league with his innovative blocking schemes and outstanding teaching ability.
"He helped the Broncos to Super Bowls during three different decades -- including back-to-back World Championships -- while forging a reputation as one of the greatest assistant coaches in NFL history. Our hearts go out to Alex's wife, Trina, and the entire Gibbs family as well as Alex's many former players and fellow coaches."
"He had a way of developing camaraderie & accountability toward one another that was unmatched in my career."@markschlereth on former #Broncos Offensive Line Coach Alex Gibbs: pic.twitter.com/EWoCs0me7t— Denver Broncos (@Broncos) July 13, 2021
Gibbs' zone-blocking scheme gave the Broncos a dominant running game behind Hall of Fame tailback Terrell Davis, which culminated in the team winning Super Bowls XXXII (1998) and XXXIII (1999).
Gibbs' NFL coaching career started in 1984 and ran through 2013. He had three separate stints with the Broncos during that span, most notably a nine-year tenure as the team's assistant head coach and offensive line coach from 1995-2003.
He ended his coaching career as an offensive line consultant for the Broncos in 2013.
Gibbs also was an assistant coach for the Atlanta Falcons (2004-06), Los Angeles Raiders (1988-89), San Diego Chargers (1990-91), Kansas City Chiefs (1993-94), Houston Texans (2008-09) and Indianapolis Colts (1992). He also spent time with the Seattle Seahawks in 2010 but abruptly retired before the first game of that season.